Fuel pump requirements
 

What do you think the minimum pump is required on a car that goes 10.66@128. W/a 1.55 60ft. 3200lbs
This is a bracket/street car a friend has.

Re: Fuel pump requirements
 

something like a Holley blue pump will get the job done. 1 gallon in 30 seconds is the flow you need on a car of that speed.

Re: Fuel pump requirements
 

Holley Black

Re: Fuel pump requirements
 

Mechanical or electric?
My street car is 3260 w/me in it, runs 10.60's @127 and has a regular old Carter mechanical pump with 3/8 lines.

Re: Fuel pump requirements
 

Funny how things change with the times. Is that 1gallon measurement thru 2 needle&seats at full drop?

Re: Fuel pump requirements
 

Fuel pumps are rated at free flow, so if you take a Holley blue and with 3/8" lines you hold the out line in a empty fuel can and run the pump for 15 seconds you should see slightly less than .5 of a gallon. This is adequate for this combo, but IMO borderline. I would use a min. of 250 gal/hr pump. Remember that line size, bends in the lines, filters, pick up location from tank, fuel regs, and fitting choices among other things can reduce the actual flow to the carb. Take caution when checking free flow. No burns....

Re: Fuel pump requirements
 

It surprises me that theres no mention of g force on the launch, thats the whole problem with a 12 PSI fuel pump. Theres a reason bigger pumps run over 20 PSI out.

Re: Fuel pump requirements
 

He's running a single blue now.
I had freshened the engine after it ate a lifter. Upped the comp to 11.1,had the heads ported and upped the cam on his request.
Only picked up 2mph from unported heads a point less compression and a cam that's 7degrees smaller on the intake lobe.
Sorta looking for answers i guess.

Re: Fuel pump requirements
 

Whats the combination? A car with a Holley 4 barrel is much easier to keep fed than say a Quadrajet on an otherwise identical application. A single Holley "Blue" electric pump should be more than adequate for a car like that with a Holley carb. My bracket car with a Holley 650 carb ran 10.2ETs at 130 MPH, 1.36 60 foot times with a single Holley blue, with a stock gas tank and 3/8" steel fuel line. I know a few guys with similar cars that run similar times with a Carter mechanical pump, but very unlikely a QJet car would get to 1/2 track under power with the same fuel system.

Re: Fuel pump requirements
 

1320/130=10.15 and thats just a jumping off point. In the 80s I had a 68 Chevelle with a Holley pump that ran 10.70s, stalled the fuel on the launch, changed the spring to the heavier Moroso spring, with no other changes the car went 10.48, and I suspect that still wasn't enough. Although I will say this car left extremely hard for a 10 sec car, which had a lot to do with why the fuel system was taxed. As far as the Q-Jet goes, I've got stories if anyone interested, I've seen this tried, no way will this work-ever.

Re: Fuel pump requirements
 

Single Holley carb.

Re: Fuel pump requirements
 

Take a moment and think about something! There is probably enough fuel in the float bowls on a Holley carb to do a burn out and make a full 1/4 mile pass before you run out of fuel at the 1/4 mile mark !!! How much fuel do you think is going to pass thru 4 little jets??? All you are trying to do is overcome the acceleration of the vehicle and keep an adequate supply of fuel going thru the carb to the engine--- Unless you have 600 inches or something like that and you putz around at the starting line a decent pump and large enough fuel lines should be able to supply adequately the needs for most applications. My .02 cents flame away if you want to .... FED 387

Re: Fuel pump requirements
 

About 20gph at 520hp if i didn't screw the math up.
1/2 lb of fuel per 1hp i think?
That's all fine accept the cust tells me it stops pulling around 6000 in high gear

Re: Fuel pump requirements
 

My car has one of the knock off holley pumps from summit. It runs 10.0@ 130 with a q jet carb. #8 line from the cell to the carb. I have a magna fuel regulator. Low 1.30
60 ft. No issues with fuel delivery. Kind of old school set up but is working OK

Re: Fuel pump requirements
 

From something I wrote a while ago.....
Even lower horsepower racecars can benefit from a detailed investigation of how to build an effective fuel system for a drag racing application. An assumption of “….if the car runs good and it 60 foots hard, then the system is OK…” is far from the truth. Many folks are comfortable with not knowing the facts. Don’t be one of them. Being informed will improve your racing results....:rolleyes:
FYI - A Holley carburetor with center hung floats has an operational float bowl volume of 0.066gallons (251.34cc) and a QJet has an operational float bowl volume of 0.022 gallons (81.94cc). The Holley when mounted fore and aft has the primary float opening the n&s under accel while the secondary is trying to close its side off. The QJ is trying to close the flow off.....When under accel g, the system line pressure (before the regulator) must oppose the g.



There is lots to the details of making a system the best for the application instead of just writing checks.


Regards to all that like this kind of stuff,:D
HB2:)
Dissident

Re: Fuel pump requirements
 

Forget to turn the fuel pump on as you pull out of the lanes and do a burnout and see how far you get.

Re: Fuel pump requirements
 

The engine quits before you finish the burnout. Been there.

Re: Fuel pump requirements
 

Yes they might die doing a burn out you definitely need to replenish the fuel that is used by applying pressure to move fuel from the reservoir to the carb float bowl ---- I said the amount of fuel CONSUMED to do the burn out and run a lap--- You don't need a 500 GPH pump and humungous pressure to accomplish this ---you need an adequate supply--- Now what is an adequate supply ?? That is a case by case scenario that trial and error and experience and advice is going to help you determine the solution to the problem--- I suppose overkill in choosing your equipment will solve it right away but do you really need to spend that much money to reach your objectives--FED 387

Re: Fuel pump requirements
 

The best bang for the buck would be an Aeromotive SS pump,has 18 lbs preset pressure.I run one on a BBC,Q-jet,1/2 in.fuel line stocker. Steady 6 1/2- 7 lbs.down the track...gsa612

Re: Fuel pump requirements
 

Regulated fuel pressure on a QJ at 5-5.5psi will supply enough fuel IF the n&s is sized correctly......pardon the digression...;)

Most if not all stock and super stock cars have the fuel supply sump (tank or cell) in the rear, so the system pressure must oppose g.....

Adequate Fuel Supply? The following chart is for gasoline.

In case you have forgotten, without data, you are just another guy with an opinion.:cool:

Regards to all that like this kind of stuff, :D

HB2:)
Dissident

Re: Fuel pump requirements
 

Yep---he needs a pump that can pump about 50 GPH so any pump that satisfies a 520 HP engines demands should work --- no need for a 500 GPH pump its overkill and might lead to other problems such as fuel blowing past the needle and seat do to over pressurization--- I think he was originally referring to a Holley carb not a Q-jet but I could be wrong--- he must remember thats it's the volume of fuel the pump has to provide pressure is a secondary factor --- pump location as well as fuel line size and number of restrictions in the line ( ie.fittings-filters-regulators-number of bends etc) is going to affect the volume of fuel that ultimately arrives at the carb

Re: Fuel pump requirements
 

Cancelling once again cannot get the chart to show up correctly....Sorry.

Re: Fuel pump requirements
 

Trying to post chart again:(
Horsepower Requires Fuel
(flow estimates for use of gasoline)
Gasoline has a heating value of approximately 19,900 Btu/lb

Hp Fuel Required
300Hp 150 lbs/hr 0.400 gal/min
400Hp 200 lbs/hr 0.533 gal/min
500Hp 250 lbs/hr 0.666 gal/min
600Hp 300 lbs/hr 0.799 gal/min
700Hp 350 lbs/hr 0.933 gal/min
800Hp 400 lbs/hr 1.066 gal/min
900Hp 450 lbs/hr 1.200 gal/min
1000Hp 500 lbs/hr 1.330 gal/min
1100Hp 550 lbs/hr 1.464 gal/min
1200Hp 600 lbs/hr 1.598 gal/min
1300Hp 650 lbs/hr 1.732 gal/min
1400Hp 700 lbs/hr 1.866 gal/min
1500Hp 750 lbs/hr 2.000 gal/min
*based on gasoline with SG 0.750, weighing 6.255 lbs/gal and a BSFC of 0.5lbs/hp-hr.
BSFC is brake specific fuel consumption in pounds of fuel per horsepower-hour.